Prediction of Vehicle Aerodynamic Heat State and Analysis of Thermal Environment Characteristics

The vehicle’s aerodynamic heat state and thermal environment characteristics in different airspaces and Mach numbers are studied using the two-temperature equation and high-temperature chemical reaction model. First, the distribution characteristics of the cold-wall heat flux of the vehicle are discussed. Second, the effects of the airflow parameter on the cold-wall heat flux are analyzed. Additionally, the range of heat flux and the boundary between continuous and rarefied flow regimes are discussed. Finally, an aerodynamic heat prediction model based on the backpropagation neural network algorithm is developed. After considering the molecular vibration excitation effect, the cold-wall heat flux increases significantly. Within the boundary layer, elevated airflow density and reduced velocities contribute to the higher heat flux. The rapid enthalpy rise causes substantial temperature gradients and a sudden increase in heat flux. The states of high enthalpy and low, medium, and high heat flux change with altitude, Mach number, and the vehicles’ characteristic length. The 55 km and 19.5 Ma condition can be regarded as the boundary of continuous and rarefied flow regimes for the waverider vehicle. The aerodynamic heat prediction model results match well with the numerical simulation results, with a maximum error of less than 5%.